Great for ball machine, serve practice and hand feeds. Lacks a bit of liveliness for groundstrokes.
Not too harsh on the arm. A thicker felt compared to the regular Wilson Trinity pressureless balls. The cardboard containers are environmentally friendlier than the plastic ones, but an even better solution would be to simply sell them in a single box without the individual 3-ball cardboard containers. Prior to the Wilson Trinity Pros, I purchased 72 of the regular Wilson Trinity balls, which came in one rectangular cardboard box. So, don't know why the same isn't done with the Trinity Pros. Again, a nice pressureless ball, but if you plan on using them for serious groundstroke drills/practice/match play, I feel the bounce just isn't close enough to a real non-pressureless ball, if you're a solid 4.5 or higher player. Note: I understand being a pressureless ball, it will "not" have the exact same bounce as a non-pressureless ball.